|
|
/**
@file
@ingroup cudd
@brief Computation of signatures.
@author Fabio Somenzi
@copyright@parblock Copyright (c) 1995-2015, Regents of the University of Colorado
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the University of Colorado nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. @endparblock
*/
#include "util.h"
#include "cuddInt.h"
/*---------------------------------------------------------------------------*//* Constant declarations *//*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*//* Stucture declarations *//*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*//* Type declarations *//*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*//* Variable declarations *//*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*//* Macro declarations *//*---------------------------------------------------------------------------*/
/** \cond */
/*---------------------------------------------------------------------------*//* Static function prototypes *//*---------------------------------------------------------------------------*/
static double * ddCofMintermAux (DdManager *dd, DdNode *node, st_table *table);
/** \endcond */
/*---------------------------------------------------------------------------*//* Definition of exported functions *//*---------------------------------------------------------------------------*/
/**
@brief Computes the fraction of minterms in the on-set of all the positive cofactors of a %BDD or %ADD.
@details The array has as many positions as there are %BDD variables in the manager plus one. The last position of the array contains the fraction of the minterms in the ON-set of the function represented by the %BDD or %ADD. The other positions of the array hold the variable signatures.
@return the pointer to an array of doubles if successful; NULL otherwise.
@sideeffect None
*/double *Cudd_CofMinterm( DdManager * dd, DdNode * node){ st_table *table; double *values; double *result = NULL; int i, firstLevel; int size;
#ifdef DD_STATS
unsigned long startTime; startTime = util_cpu_time(); dd->num_calls = 0;#endif
table = st_init_table(st_ptrcmp, st_ptrhash); if (table == NULL) { (void) fprintf(dd->err, "out-of-memory, couldn't measure DD cofactors.\n"); dd->errorCode = CUDD_MEMORY_OUT; return(NULL); } size = dd->size; values = ddCofMintermAux(dd, node, table); if (values != NULL) { result = ALLOC(double,size + 1); if (result != NULL) { if (Cudd_IsConstantInt(node)) firstLevel = 1; else firstLevel = cuddI(dd,Cudd_Regular(node)->index); for (i = 0; i < size; i++) { if (i >= cuddI(dd,Cudd_Regular(node)->index)) { result[dd->invperm[i]] = values[i - firstLevel]; } else { result[dd->invperm[i]] = values[size - firstLevel]; } } result[size] = values[size - firstLevel]; } else { dd->errorCode = CUDD_MEMORY_OUT; } }
if (Cudd_Regular(node)->ref == 1) FREE(values); st_foreach(table, cuddStCountfree, NULL); st_free_table(table);#ifdef DD_STATS
(void) fprintf(dd->out,"Number of calls: %d\n", dd->num_calls); (void) fprintf(dd->out,"Time to compute measures: %s\n", util_print_time(util_cpu_time() - startTime));#endif
if (result == NULL) { (void) fprintf(dd->out, "out-of-memory, couldn't measure DD cofactors.\n"); dd->errorCode = CUDD_MEMORY_OUT; } return(result);
} /* end of Cudd_CofMinterm */
/*---------------------------------------------------------------------------*//* Definition of internal functions *//*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*//* Definition of static functions *//*---------------------------------------------------------------------------*/
/**
@brief Recursive Step for Cudd_CofMinterm function.
@details Traverses the %DD node and computes the fraction of minterms in the on-set of all positive cofactors simultaneously. It allocates an array with two more entries than there are variables below the one labeling the node. One extra entry (the first in the array) is for the variable labeling the node. The other entry (the last one in the array) holds the fraction of minterms of the function rooted at node. Each other entry holds the value for one cofactor. The array is put in a symbol table, to avoid repeated computation, and its address is returned by the procedure, for use by the caller.
@return a pointer to the array of cofactor measures.
@sideeffect None
*/static double *ddCofMintermAux( DdManager * dd, DdNode * node, st_table * table){ DdNode *N; /* regular version of node */ DdNode *Nv, *Nnv; double *values; double *valuesT, *valuesE; int i; int localSize, localSizeT, localSizeE; double vT, vE; int size = dd->size;
statLine(dd);#ifdef DD_STATS
dd->num_calls++;#endif
if (st_lookup(table, node, (void **) &values)) { return(values); }
N = Cudd_Regular(node); if (cuddIsConstant(N)) { localSize = 1; } else { localSize = size - cuddI(dd,N->index) + 1; } values = ALLOC(double, localSize); if (values == NULL) { dd->errorCode = CUDD_MEMORY_OUT; return(NULL); }
if (cuddIsConstant(N)) { if (node == DD_ZERO(dd) || node == Cudd_Not(DD_ONE(dd))) { values[0] = 0.0; } else { values[0] = 1.0; } } else { Nv = Cudd_NotCond(cuddT(N),N!=node); Nnv = Cudd_NotCond(cuddE(N),N!=node);
valuesT = ddCofMintermAux(dd, Nv, table); if (valuesT == NULL) return(NULL); valuesE = ddCofMintermAux(dd, Nnv, table); if (valuesE == NULL) return(NULL);
if (Cudd_IsConstantInt(Nv)) { localSizeT = 1; } else { localSizeT = size - cuddI(dd,Cudd_Regular(Nv)->index) + 1; } if (Cudd_IsConstantInt(Nnv)) { localSizeE = 1; } else { localSizeE = size - cuddI(dd,Cudd_Regular(Nnv)->index) + 1; } values[0] = valuesT[localSizeT - 1]; for (i = 1; i < localSize; i++) { if (i >= cuddI(dd,Cudd_Regular(Nv)->index) - cuddI(dd,N->index)) { vT = valuesT[i - cuddI(dd,Cudd_Regular(Nv)->index) + cuddI(dd,N->index)]; } else { vT = valuesT[localSizeT - 1]; } if (i >= cuddI(dd,Cudd_Regular(Nnv)->index) - cuddI(dd,N->index)) { vE = valuesE[i - cuddI(dd,Cudd_Regular(Nnv)->index) + cuddI(dd,N->index)]; } else { vE = valuesE[localSizeE - 1]; } values[i] = (vT + vE) / 2.0; } if (Cudd_Regular(Nv)->ref == 1) FREE(valuesT); if (Cudd_Regular(Nnv)->ref == 1) FREE(valuesE); }
if (N->ref > 1) { if (st_add_direct(table, node, values) == ST_OUT_OF_MEM) { FREE(values); return(NULL); } } return(values);
} /* end of ddCofMintermAux */
|
